package com.snail.service.impl;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

/**
 * @Author 【swg】.
 * @Date 2017/12/12 15:02
 * @DESC
 * @CONTACT 317758022@qq.com
 */
@Component
@Slf4j
public class RedisLock {
    @Autowired
    private StringRedisTemplate redisTemplate;

    /**
     * 加锁
     * value:当前时间+超时时间
     */
    public Boolean lock(String key, String value){
        if(redisTemplate.opsForValue().setIfAbsent(key,value)){
            return true;
        }
        String currentValue = redisTemplate.opsForValue().get(key);
        /*如果锁过期*/
        if(!StringUtils.isEmpty(currentValue) && Long.parseLong(currentValue) < System.currentTimeMillis()){
            //获取上一个锁的时间
            String oldValue = redisTemplate.opsForValue().getAndSet(key,value);
            if(!StringUtils.isEmpty(oldValue) && oldValue.equals(currentValue)){
                return true;
            }
        }
        return false;
    }


    /**
     * 解锁
     */
    public void unlock(String key,String value){
        try {
            String currentValue = redisTemplate.opsForValue().get(key);
            if(!StringUtils.isEmpty(currentValue) && currentValue.equals(value)){
                redisTemplate.opsForValue().getOperations().delete(key);
            }
        } catch (Exception e) {
            log.error("【redis分布式锁解锁异常】:{}",e);
            e.printStackTrace();
        }
    }
}
